Sun Roof problems of the 2013 Volkswagen Passat

While driving 65 mph and without warning the sunroof of my 2013 Volkswagen Passat exploded outwards, creating an approximately 18" hole. Some glass fell inside but the majority of the glass exited the car. The outside temperature was ~65 degrees, no other windows were open and the sunroof was fully closed; the interior cover of the sunroof was open. Neither the heat or air condition were on. I was not on my cell phone and the music volume was on low. I am the first owner of this car, having taken possession 87 days ago. The dealership will not accept culpability and has stated I would have to prove a factory defect led to the explosion of the sunroof. An internet search indicates the exploding sunroof is not an unheard of problem. We continue to address this issue with the dealer but as of this moment, indications are they will expect our insurance to cover the costs of repair.